The image was captured by physicist David Nadlinger from the University of Oxford, and it's been awarded the overall prize in the UK's Engineering and Physical Sciences Research Council photo competition.

To give you a little perspective on the size of this set-up, the atom is being held in place by electric fields emanating from those two metal needles on either side of it.

The distance between them is about 2 millimetres (0.08 inch).

The atom is being illuminated by a blue-violet laser. The energy from the laser causes the atom to emit photons which Nadlinger could capture on camera using a long exposure.

The whole thing is housed inside an ultra-high vacuum chamber and dramatically cooled to keep the atom still. Nadlinger took this photo through the window of the vacuum chamber.

"The idea of being able to see a single atom with the naked eye had struck me as a wonderfully direct and visceral bridge between the miniscule quantum world and our macroscopic reality," he explains.

"A back-of-the-envelope calculation showed the numbers to be on my side, and when I set off to the lab with camera and tripods one quiet Sunday afternoon, I was rewarded with this particular picture of a small, pale blue dot."

Not only do these types of laser-cooled atomic ions allow researchers to study and harness the properties of the quantum world, they can also be used to build atomic clocks and future quantum computers.